Improved mode of preserving-  wood



STATES PA'IET Orr eHARLEs E. CLARKE, eEoReEI RADLEY, AND- JOHN OCLIEEORD, or RUE.

. EALO, NEvvT YORK IMPROVED MODE OF PRESERVING- WOOD.

Specfcattonforming part of Letters Patent N o. 67,104, lated July 23, 1867.

.To all whom it may concern Be it known that we, CHARLES E. CLARKE,

, GEORGE HADLEY, and JOHN C. CLIFFORD, of

the city of Bualo, in the county of Erie and State of New York, have invented a new and useful Process of' Saturatin g Wood with any Preservative Liquid, or with any solid whichurating wood with vapor previously to satul rating it with any suitable oleaginous or preservative material, and then by using the said oleaginous or preservative material as a condenser, causing a thorough saturation of the wood with such material.

To more plainlystate our process, we will refer to it as consisting of two parts or stages.

In the first the wood, which may be used either dry and seasoned or green and watersoaked, is filled with an atmosphere of' some kind of vapor. This is best effected by heating it in a suitable vessel, out of contact of air, in a gentle current of' vapor, such as steam. The air and water which fill its tissues are expelled and carried off, and their place lled by the vapor employed for expelling them.

In the second part of our process the wood, while in the above-mentioned condition, and still hot, is immersed in the saturating liquid. Here it is allowed to remain until, by cooling, the vapor condenses, and the inimersin g liquid consequently enters and fills the vacuum cells or vtissues which were previously occupied and filled by the vapor in the gaseous form.

By the first part of the process the wood is filled with condensable vapor; by the second, the vapor 41s condensed, and the room in the cells or tissues thus afforded by the vapor occupying a smaller space is occupied by the preserving or saturatin g liquid.

-leading` from the steam-boiler B.

'the condensable vapor.

For the first part of' the process we prefer the use of steam or superheated steam, but we may employ with equal efficiency the vapor of' any substance whatever which' has the proper degree of volatility.

For the second part of the process the liquid employed may be vegetable or animal fats and oils, gas-tar, gas-tar distillates, gastar cement, petroleum, 'petroleum-distillates, parallne, asphaltuni, rosin or other resinous bodies, varnishes; saline solutions, such as corrosive sublimate, chloride of zinc, sulphate of iron, and other analogous or known substances used for the purposes ot' impregnating wood 5 earbolic acid; coloring matters may also be employed or,A in short, any useful known liquid,or any useful known solid, or mixtures of' solids and liquids, which can be brought to the Huid state may be used.

To perform our process, we place the pieces Aof wood a a ct in the vessel A, and into the vessel A we introduce wet steam,'either common or superheated, by means of the pipe I),

We continue the ilow or circulation of' steam through the vessel A, amid the wood, as indicated by the arrows, for such a length of' ,time as will insure a thorough saturation ofthe wood with The waste steam escapes at o.

One action of the steam or vapor upon the wood is to soften the resinous and fermentable matters contained in the wood. Another action is to expand the wood, open its pores, and expel the air contained in the pores or tissues.

After the wood is thus treated, the steam is shut off, and while the vvapor is uncondensed in the pores or tissues, we flow into the vessel A, from a tank, I), by means of the pipe c, any oleaginous or preserving material. The quantity flowed into the vessel A should be sufficient to entirely immerse the pieces of wood which have been saturated with the vapor or steam. The oleagiiious, saline, or other useful material used being cold or comparativelycool with respect to the temperature of' the vapor first used, a rapid condensation of' the vapors takes place within the cells or tissues ofthe wood, and these cells, which but a moment before were filled withthe expanded is removed from the bathv of immersion. preserving or protecting material is then gas or vapor, become suddenly lled with the oleaginous substances or preserving materials, which constitute or form the bath of immersion.

To insure a perfect saturation of the wood with the preserving material, we allow the soaking process to go on for some hours, say from four to twelve hours, according to the thickness and nature of the material to be saturated.

The principle of our` invention is a very plain and simple one, to wit: The vapor or steam heats and expands the wood, softens and displaces, or disperses, all resinous or sappy substances, and also eXpels the air in the cells. rlhis done, it is obvious that when the steam is condensed, the spaces or cells in the wood which it occupied will no longer be filled to their capacity, and as this condensation takes place so soon as the wood becomes immersed by the oleaginous, saline, or other material, there is an immediate influx into these cells ofthe bath-preserving material.

Our main discovery is to use a hot condensable vapor to prepare the way for a cool, solid, condensing fluid, such fluid being the preserving or protecting material for the wood. As a given quantity of vapor occupies a space far greater than that which the condensed fluid of the same occupies, it naturally follows that space for the influx of the preserving or protecting material is provided at the moment this vapor is condensed by the influx of the preserving or protecting materials into the vessel.

When the wood is thoroughly saturated it The pumped up, for reuse, ont of the vessel A in- Y n to the tank by means of the apparatus E, and

This same process may be usefully employed in the saturation of woods With coloring matters for the purposey of making imitations of the handsome natural Woods used in the manufacture of costly furniture.

Wood treated by our process may be employed with great advantage for cabinetwork, interior wood-work of dwellings, ties for railroads, sills for bridges, and for a multitude of purposes, useful and ornamental, as Well as for those founded solely on its freedom from speedy decay.

The form of the apparatus employed, or its particular construction, is not very material, any further than that it must fulfill the essential conditions of first saturating the wood with vapor as a means of afterward filling it with the requisite preserving and protecting substances.

When superheated steam is employed, av

boiler for generating the steam, a superheater for raising the temperature of the steam above 2120 F., and a vessel or chamber for holding the wood will all, if not absolutely necessary, be found convenient and serviceable.

A single boiler or still, with a suitable condenser attached, may be employed both for generating the Vapor and for holding the wood under treatment, if so constructed as to be kept lled with a continuously renewed atmosphere of the vapor in the first part of the process, and to receive the infiltrating liquid in the second.

What we claim as our invention, and desire to secure by Letters Patent, is-

lhe within-described process of treatin g wood for the purpose of preserving, protecting, solidifying, or coloring the same.

CHARLES E. CLARKE.

GEORGE HADLEY.

J. C. GLlFFORD.

Witnesses:

E. B. FoRBUsi-I, B. H. MUEBLE. 

